Add support for m32rx.

	Add support for m32rx.
	* config/tc-m32r.c (enable_m32rx): New static global.
	(enable_special,warn_explicit_parallel_conflicts,optimize): Ditto.
	(allow_m32rx): New function.
	(M32R_SHORTOPTS): Add `O'.
	(md_longopts): Add --m32rx plus several warning options.
	(md_parse_option): Handle new options.
	(md_show_usage): Print them.
	(md_begin): Enable m32rx.
	(OPERAND_IS_COND_BIT): New macro.
	(first_writes_to_seconds_operands): New function.
	(writes_to_pc,can_make_parallel,make_parallel): New functions.
	(target_make_parallel,assemble_two_insns): New functions.
	(md_assemble): Recognize "insn1 -> insn2" and "insn1 || insn2".
	If optimizing and m32rx, try to make consecutive insns parallel.